A series of deadly bomb attacks has killed more than 100 people in Shia areas of Baghdad and the town of Khalis, to the north of the capital.

At least 60 people were killed and 25 injured in a suspected double suicide bombing in a popular Baghdad market.

Earlier, more than 40 people died and 80 were injured in three co-ordinated blasts in the town of Khalis.

The attacks came despite a major security operation in Baghdad aimed at reducing the level of violence.

The Baghdad attack, at a market in the north-eastern al-Shaab district, occurred at about 1830 (1530GMT).

The Associated Press says that the al-Shaab area was one of the first places US and Iraqi forces concentrated their efforts to root out Shia militias under the current security plan.

Khalis targeted

Hours before the Baghdad bombing, three explosions rocked the town of Khalis, about 80km (50 miles) to the north.

There was a huge blast near some shops. I threw myself on the floor and covered my head with my hands

Ali SadiqKhalis civil servant

Police said the first two explosions came in quick succession, one of them near a market, and the second near a court building.

The third apparently targeted the security forces. At least one was reported to be a car bomb.

There were unconfirmed reports of mortar attacks and further explosions as rescuers tried to reach the scene.

The BBC's Jim Muir, in Baghdad, says the attackers' objective, as in so many similar outrages, appears to have been simply to kill and maim as many ordinary people as possible as part of a campaign of sectarian provocation.

Khalis has been hit by a number of attacks in the past. In January the main market came under mortar attack.

Iraqi Prime Minister Nouri Maliki quickly condemned the attacks and pledged to track down those responsible.

Bloody week

One witness in Khalis told Reuters that he saw at least eight bodies lying in the streets.

"There was a huge blast near some shops. I threw myself on the floor and covered my head with my hands," said civil servant Ali Sadiq.

"Within minutes I heard another blast and then a third."

The AFP news agency said at least nine mortar attacks also hit residential areas while two roadside bombs exploded in a main street near the market

The attacks in Khalis came as a bloody week unfolded in Iraq.

About 55 people died in a bombing in a Shia area of the town of Talafar on Tuesday.

Gunmen, many alleged to be policemen, then killed about 70 Sunni men in a shooting spree on Wednesday.